A multi-tenant CRM stores contacts. Each contact has an email that must be unique within a tenant, and a phone number that must be unique within a tenant. The tenantId is the partition key. Which design enforces both uniqueness constraints?

Add a composite unique key on /email and /phoneNumber.

Use the email as the document id and add a unique key on /phoneNumber.

Add two unique keys: one on /email and one on /phoneNumber.

Add a single unique key on /email and use a stored procedure to check phone uniqueness.

A blogging platform stores authors and their articles. Articles are frequently updated, and authors are rarely updated. The team wants to avoid duplicating author data across every article. Which modeling approach should they use?

Embed the entire author document inside each article.

Store articles with an authorId reference and keep authors in a separate container.

Store authors and articles in the same container with a type discriminator and no references.

Store articles with a copy of the author's name and bio.

A team is introducing a new field to an existing document type in a Cosmos DB container. The application must handle both old and new documents during a rolling deployment. Which approach should they use?

Add a schemaVersion field to new documents and write application code that handles both versions.

Use a stored procedure to transform documents on read.

Create a new container for the new schema and move all data to it.

Run a migration job to update all existing documents to the new schema before deploying the application.

In Azure Cosmos DB, what is the purpose of using a reference (e.g., storing an id or a link) to another document instead of embedding the related data?

To allow the related document to be updated independently without affecting the referencing document.

To automatically maintain referential integrity between documents.

To eliminate the need for a partition key in the container.

To ensure that related documents are always stored in the same partition.

Microsoft Certified:Azure Cosmos DB Developer Specialty

Domain 1Objective 1

Design and Implement a Non-Relational Data Model for Azure Cosmos DB for NoSQL DP-420 Practice Questions (Page 4)

Part of the Design and implement data models domain, which makes up ~45% of our current practice bank. Microsoft does not publish an official question count, but from its 100-minute exam (~40–65 total, ~18–29 in this domain), expect 3–4 from this objective — we provide 27 practice questions to prepare you well beyond it. (estimate)

27questions here

6free pages

10concepts

Questions 16–20

16expert · hard
A multi-tenant CRM stores contacts. Each contact has an email that must be unique within a tenant, and a phone number that must be unique within a tenant. The tenantId is the partition key. Which design enforces both uniqueness constraints?
Select an answer first
17application · medium
A blogging platform stores authors and their articles. Articles are frequently updated, and authors are rarely updated. The team wants to avoid duplicating author data across every article. Which modeling approach should they use?
Select an answer first
18application · medium
A team is introducing a new field to an existing document type in a Cosmos DB container. The application must handle both old and new documents during a rolling deployment. Which approach should they use?
Select an answer first
19foundation · easy
Which property is commonly added to a document to support schema versioning?
Select an answer first
20foundation · easy
In Azure Cosmos DB, what is the purpose of using a reference (e.g., storing an id or a link) to another document instead of embedding the related data?
Select an answer first

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